This invention relates to a custom-fitted ankle splint.
The invention has particular application in the orthopedic medical field, where ankle sprains or fractures are often supported and immobilized with a splint or brace so that the patient can continue to walk while the injury heals. One typical such injury is a sprain of the anterior talofibular ligament at the interior margin of the lateral malleolus. In such cases, it is essential to splint the ankle in such a way as to stabilize the ankle against eversion and inversion while permitting dorsiflexion and planoflexion necessary for normal walking and therapeutic exercise. It is also desirable for the splint to be sufficiently compact to fit within a conventional shoe. This facilitates sufficient use of the injured ankle during healing so that muscle atrophy is avoided or minimized.
The invention takes advantage of polymer chemistry to permit quick and easy molding of a splint to the ankle. Shock attenuation is increased since the custom fit provides spreads contact between the splint and the ankle over a wider surface area. Similarly, the close, custom fit is in distinct contrast to so called "one size fits all" braces or splints wherein a rigid outer shell provides support, and a relatively thick cushioning pad, for example, an inflatable bladder, must be utilized to fill the voids created between the "one sized" rigid shell and the foot, ankle and lower leg.
Therefore, in the particular embodiment of the invention disclosed in this application, the splint will accommodate a wide range of sizes and can be fitted to either the right or left ankle. Thus, a much reduced inventory of splints is required. This feature also substantially reduces design and manufacturing costs, and promotes use through ease of fitting. The custom-fit of the splint permits easy removal for bathing, dressing or adjustment, and easy and mistake-proof replacement even by children.
Prior art ankle splints include numerous types of splints and braces which typically include a soft component to place near the skin and a hard, shell-like preformed outer cover having a shape approximating a "normal" ankle. The soft component, for example, fiber padding, foam or an air bladder, is intended not only to provide a cushion, but also to accommodate itself to the varying configurations of differing sized and shaped body parts. For this reason, the cushioned part is substantially greater in thickness than required merely to provide the required amount of shock attenuation and protection from the rigid substrate. Such devices are sufficiently `generic` in size and shape that they usually are required to be held in place by straps or bands.
Other prior art ankle braces include pads which are constructed of thermosetting materials which are heated and then formed to the body while heated. These products require a source of heat, and are susceptible to either over-or-underheating. In addition, body heat itself can soften or increase the flexibility of the pad, thereby decreasing the effectiveness of the protection offered by the pad.
Applicant's prior U.S. Pat. No. 5,637,077 provides a solution to some of the problems described above, but is a unitary structure which has definite forward and rearward sides. Also, because the opposing sides of the splint are integrally-formed to each other by means of a unitary heel support member, lengthwise adjustment of the splint by shortening or lengthening the heel support is not possible.
The present invention permits quick and easy application of an ankle splint to a body part in such a way as to achieve a true custom fit. The moisture curable resin system used results in a very rigid ankle splint which holds the shape of the molded splint to a very high degree. No heat is required, and a source of water is the only additional material necessary to achieve a cure. Atmospheric moisture alone will cure the splint into its hardened position in a relatively short period of time, but in practice the resin in or on the splint will typically be activated by dipping in water and then removing the excess by rolling the splint in a towel immediately before application.